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  1. #61
    Hexavalent's Avatar
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    What is "summer speed" emulsion?
    - Ian

  2. #62

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    Do it be about Donna or Susann? Susann, I hear was really fast back in "The Day".

  3. #63
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    I am guessing you are referencing post #38 (??) "...ASA 100 (summer speed) ortho ("X2Ag")..." I can see how that was confusing. I meant that the emulsion is ASA 100 in the summer, assuming full sun, mid-day, and a high energy developer. That's the thing with pre-modern emulsions. It is meaningless to assign a speed to them without specifying the shooting conditions. Every photography book published in the late 1880's and early 1900's had a chart of latitudes and times of year with numbers like filter factors to estimate exposure compensation (i.e. "speed"). Since the emulsions see very little beyond UV, the higher the UV, the "faster" the emulsion. "x2Ag" is around ASA 25 at Christmas time.
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  4. #64
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    Thanks,

    I figured it was in regard to "colour-blind".

    Summer speed is probably mid-winter here in Ottawa

    Personally, I'd prefer to go panchro and not have to worry.

    Quote Originally Posted by dwross View Post
    I am guessing you are referencing post #38 (??) "...ASA 100 (summer speed) ortho ("X2Ag")..." I can see how that was confusing. I meant that the emulsion is ASA 100 in the summer, assuming full sun, mid-day, and a high energy developer. That's the thing with pre-modern emulsions. It is meaningless to assign a speed to them without specifying the shooting conditions. Every photography book published in the late 1880's and early 1900's had a chart of latitudes and times of year with numbers like filter factors to estimate exposure compensation (i.e. "speed"). Since the emulsions see very little beyond UV, the higher the UV, the "faster" the emulsion. "x2Ag" is around ASA 25 at Christmas time.
    Last edited by Hexavalent; 06-27-2013 at 10:45 PM. Click to view previous post history.
    - Ian

  5. #65
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    But the ideal is no such thing as summer speed. The speed should be the same all year round. That is my goal and that is the goal of the ANSI standards committee. If you do it right, the speeds do not vary with the seasons.

    Oh dear. Someone has something wrong here.

    PE

  6. #66
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    Panchromatic emulsion is indeed a very fine goal. Best luck to both of us (and all other serious cooks). I'm almost there. I hope the same for you. I will be proud to use my own pan film, but I'll still make and use colorblind, and also ortho. They all have their own personalities and uses.
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  7. #67
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    How DO you make an emulsion be the same speed all your round? Do you desensitize it to UV?

    Pachromatic would be great, except you have to coat it in the dark, right? I'm not that good!
    All this has happened before, and all this will happen again.

  8. #68
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    Yes, most commercial films today are overcoated with a UV blocker.

    And no, I don't like to coat in total darkness either. I've worked in a black lab too many times to know it is not easy and therefore I commonly work in safelight conditions with, at most, ortho films.

    PE

  9. #69
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    As an aside, if you want to see some truly bizarre color->grey rendering, try some short IR imagesetter film - it's UV/blue and red/IR sensitive, with a green blindness. (It does require some tricks just to get the focussing right).
    - Ian

  10. #70

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    You do not have to work in a Black Room. A Cheap (~$200) generation 1 IR manacle takes a bit of adjustment. But I use one all the time. Worst part is- distorted depth perception.
    Denise- Not to be cynical, but "almost there" can be much longer than "halfway there". You and I are working with different systems. But I hope that, once you get "There" you will publish info on TLF.
    Ian, If you know the dye system of IR imagesetter, just add some erythrosine and you have a panchro emulsion. No?



 

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